Feeding mechanism for sewing machines



July 20, 1943.; L. c. MARSAC FEEDING MECHANISMS FOR SEWING MACHINES V r Filed arch 1,- 1941 \NVENTIOR Leonard C. Man ac.

ATTORNEY Patented July 20, 1943 FEEDING MECHANISMFOR SEWING MACHINES Leonard C. Marsac, Cranford, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application March 1, 1941, Serial No. 381,222

6 Claims.

This invention relates to improvements in feeding mechanisms for sewing machines and more particularly to an adjustable means for mounting a feed-dog upon a feed-bar.

A primary object of the present invention is to provide a simpl and inexpensive means for securing a feed-dog upon a feed-bar whereby the feed-dog may be angularly adjusted relative thereto. It is desirable to have the feed-dog adjustably mounted upon the feed-bar so that the inaccuracies of manufacture may be overcome to the end that the feeding surface of the feed-dog may be properly disposed in a horizontal position. Furthermore, the provision of an adjustable feed-dog permits the dog to be tilted so that its feeding surface is disposed at an angle to the horizontal with either the front or the rear end thereof raised. If the front end of the feed-dog is raised, the work will be fed to the needle faster than it is fed away therefrom and, therefore, a gathering effect is produced in the work. With the rear end of the feed-dog raised above the level of the front end, a stretching of the work results.

A further object of the invention is to provide a feeding mechanism of simple construction that is designed to permit access to the sewing machine looper element.

With these and other objects in view, as will hereinafter appear, the invention consists in the devices, combinations and arrangements 'of parts described in connection with the accompanying drawing, which illustrates a preferred embodiment of the invention and in which;

Fig. 1 is a front end elevation of the improved feeding mechanism.

Fig. 2 is a view showing the supporting means for the feed-dog and the work-support with the feed-dog tilted to an inclined position with the rear end of the dog raised, shown in solid lines, and with the front end of the dog raised, shown in dotted lines.

Fig. 3 is a disassembled perspective View showing the feed-bar, feed-dog, and the supporting screws.

Fig. 4 is a vertical section taken substantially on line 4-4 of Fig. 1.

The sewing machine illustrated in Fig. 1 has the usual work-supporting frame 2 provided with a throat-plate 3 which is mounted thereon.

Suitably journaled in and lengthwise of the frame 2 is the looper-actuating shaft 4 carrying a loop-taking element in the form of a rotary wind-type looper 5. The looptaking element 5 cooperates in the usual manner with the reciprocatingneedle 6.

Also suitably journaled lengthwise within the frame 2 are the feed advance and return rockshaft, not shown, and the feed-lift rock-shaft 1 upon which are mounted,'respective1y, the feedrocker 8 and the feed-lift crank 9. The feed-bar I6 is provided with pintle apertures II which re- .ceive the pintles l2 that pivotally secure the feed bar I!) to the feed-rocker 8, Pivotally secured to the feed-lift crank 9 is the slide-block 13 which is received by the slideway [4 provided in one end of the feed-bar Ill. The feeding mechanism just described is shown more in detail in the patent granted to Richard Kaier, July 2, 1940, No. 2,206,285. Other types of mechanism may be used for operating the present feed-bar.

The feed-dog I5 is provided with a vertically positioned plate-like shank l6 which is formed with a substantially centrally located aperture H. The aperture I1 is formed so that the operator may readily have access to the loop-taking element 5. The feed-bar I0 is provided with a cut-out or recess defined by the arcuately shaped shoulder or bearing portion l8 and the vertically disposed portion 23. The lower circularly edged or bearing portion IQ of the feeddog shank I6 is received within said recess. Screws 20, passing through arcuate slots or enlarged screw receiving holes 2| provided in the shank I6, are received by the threaded holes 22 provided in the vertical portion 23 of the feedbar It. As the circular bottom edge portion IQ of the shank I6 is in complete contact with the arcuately shaped shoulder l8, adjustment of the feed-dog I5 is accomplished by shifting the same about a horizontal axis which is located within the aperture H and therefore remote from the feed-bar 10. Such shifting will thereby tilt the top surface of the feed-dog I5 relative to the horizontally disposed throat-plate 3. It is to be seen therefore, that the feed-dog I5 maybe tilted through a wide range of angular adjustment relative to the throat-plate 3 withoutappreciably affecting the vertical adjustment thereof.

Having thus set forth the nature of the invention, what I claim herein is:

1. A feed-dog for sewing machines, comprising, a plate-like shank, and spaced work-engaging teeth carried by the upper portion of said shank, said shank being provided with a substantially centrally located clearance aperture and an arcuately shaped lower supporting bearing-portion, said shank being adapted to be secured to a feed-bar and being formed with at least one clamp-screw receiving aperture.

2. A feed-bar for sewing machines, comprising, a rigid member having intermediate its ends a depending portion formed with an arcuately shaped recess adapted to receive a feeddog, said depending portion being provided with at least one threaded aperture adapted to receive a feed-dog clamping screw.

3. A feed-bar for sewing machines, comprising, a rigid member having intermediate its ends a depending portion formed with a feeddog supporting surface, said surface including a vertically disposed portion and an arcuately shaped shoulder adjacent to and extending at right angles from said vertically disposed portion, said vertically disposed portion being provided with at least one threaded aperture adapted to receive a feed-dog clamping screw.

4. In a feeding mechanism for sewing machines, the combination with a feed-bar provided with an arcuately shaped recess, of a feeddog having a depending frame formed with a substantially centrally located aperture, the bottom portion of said frame being arcuate in shape and provided with at least one arcuately shaped screw-receiving slot, said frame being mounted within said recess, and means including at least one screw to secure said frame within said recess so that the frame may be turned within said recess and relative to said feed-bar about an axis located within said frame aperture, said screw passing through said slot to be threaded into said feed-bar.

5. In a feeding mechanism for sewing machines, the combination with a feed-bar provided with an arcuately shaped recess, of a feeddog having a depending shank, the bottom portion of said shank being formed as an arcuately shaped bearing portion and being provided with at least one clamp-screW-receiving slot, said arcuately shaped bearing portion being slidingly mounted within said recess, and means including at least one clamp-screw to secure said shank within said recess so that it may be turned within said recess and relative to said feed-bar, said clamp-screw passing through said slot and being threaded into said feed-bar.

6. In a feeding mechanism for sewing machines, the combination with a feed-bar provided with an arcuately shaped recess, of a feeddog having a depending shank, the bottom portion of said shank being arcuate in shape and slidingly received by said recess, and means associated with the bottom portion of said shank for adjustably securing the same within said recess so that the shank may be turned within the recess and relative to said feed-bar.

LEONARD C. MARSAC. 

